CN208028620U

CN208028620U - A kind of lithium battery is full of automatically cutting off protection circuit

Info

Publication number: CN208028620U
Application number: CN201820378803.4U
Authority: CN
Inventors: 杨芹; 张耀庭
Original assignee: Jin Xinyu Power Supply (shenzhen) Co Ltd
Current assignee: Jin Xinyu Power Supply (shenzhen) Co Ltd
Priority date: 2018-03-20
Filing date: 2018-03-20
Publication date: 2018-10-30
Anticipated expiration: 2028-03-20

Abstract

A kind of lithium battery of the utility model offer, which is full of, automatically cuts off protection circuit; including secondary commutation filter circuit, cut-out switch circuit, D/C voltage output circuit, voltage and current sample circuit and control circuit; the secondary commutation filter circuit, cut-out switch circuit, D/C voltage output circuit, voltage and current sample circuit and control circuit sequence are electrically connected, and the control circuit is also electrically connected with cut-out switch circuit.The utility model is effectively monitored to power supply current limliting, and to the charge and discharge state of lithium battery, and charge circuit is automatically cut off when battery being made to be full of；Charge circuit is automatically cut off to prevent from damaging battery under the abnormality that charges, and enhances the reliability of system.

Description

A kind of lithium battery is full of automatically cutting off protection circuit

Technical field

The utility model is related to charge protector field, specially a kind of lithium battery, which is full of, automatically cuts off protection circuit.

Background technology

Due to the chemical characteristic of lithium battery, during charging normal use, internal generation electric energy and chemical energy are mutual The chemical reaction of conversion, and under certain conditions, inside battery such as will be caused to its overcharge, overdischarge or overcurrent Chemical side reactions can seriously affect the performance and service life of battery after side reaction aggravation, and there may be bulk gas, So that cell internal pressure is increased rapidly after-explosion, causes safety problem；It is filled into power supply in addition, cell voltage and electric current can also pour in down a chimney Inside electric appliance, or even the internal circuit and its element of mains charger can be damaged, to be impacted to circuit, make circuit element Safety and reliability reduce.

Utility model content

To solve the above-mentioned problems, a kind of lithium battery of the utility model offer is full of protection circuit is automatically cut off, to power supply Current limliting, and the charge and discharge state of lithium battery is effectively monitored, charge circuit is automatically cut off when battery being made to be full of；It is charging Charge circuit is automatically cut off under abnormality to prevent from damaging battery, enhances the reliability of system.

The technical solution adopted in the utility model is：A kind of lithium battery is provided full of automatically cutting off protection circuit, feature It is：Including secondary commutation filter circuit, cut-out switch circuit, D/C voltage output circuit, voltage and current sample circuit and control Circuit, the secondary commutation filter circuit, cut-out switch circuit, D/C voltage output circuit, voltage and current sample circuit and control Circuit sequence is electrically connected, and the control circuit is also electrically connected with cut-out switch circuit.

Further, the control circuit includes control chip U6 and IC chip U5, the control chip U6 and IC chip U5 is electrically connected, the IC chip U5 and the electrical connection of voltage and current sample circuit；

The cut-out switch circuit includes triode Q5 and field-effect tube Q6；

The drain electrode of the field-effect tube Q6 is electrically connected with the output end of secondary commutation filter circuit, the D/C voltage output electricity The input terminal on road is electrically connected with the source electrode of field-effect tube Q6, and the collector of the grid and triode Q5 of the field-effect tube Q6 is electrically connected It connects, the base stage and emitter of the triode Q5 are electrically connected with control chip U6.

Further, the control chip U6 is also electrically connected with for delay cutoff, protects the capacitance C24 of circuit, described It is electrically connected respectively with control chip U6 and IC chip U5 after one end series resistance R51 of capacitance C24, the capacitance C24's is another End ground connection.

Further, the control chip U6 is 555 timers.

Further, the voltage and current sample circuit is also electrically connected with feedback control circuit, the feedback control circuit Also it is electrically connected with control circuit.

Compared with prior art, the utility model effectively monitors the charge and discharge state of lithium battery, and battery is made to be full of When automatically cut off charge circuit；To power supply current limliting, prevent from damaging under the abnormality that charges to automatically cut off because of overcurrent charging back Road is to prevent from damaging battery；The capacitance C24 for protecting circuit for delay cutoff is added in circuit, avoids power circuit False triggering action caused by pulse signal and the interference of other noise signals when switch, while battery no-voltage being made to enter, increase The strong reliability of entire charging system.

Description of the drawings

Fig. 1 is the circuit module schematic diagram of the utility model；

Fig. 2 is the circuit diagram of the utility model.

Specific implementation mode

For the ease of the understanding of those skilled in the art, below in conjunction with the drawings and specific embodiments to the utility model make into One step is described in detail.

A kind of lithium battery is provided full of protection circuit is automatically cut off, as shown in Figure 1, including secondary commutation filter circuit 1, cutting Disconnected switching circuit 2, D/C voltage output circuit 3, voltage and current sample circuit 4 and control circuit 5, the secondary commutation filter circuit 1, cut-out switch circuit 2, D/C voltage output circuit 3, voltage and current sample circuit 4 and control circuit 5 are sequentially electrically connected, the control Circuit 5 processed is also electrically connected with cut-out switch circuit 2.The voltage and current sample circuit 4 is also electrically connected with feedback control circuit 6, The feedback control circuit 6 is also electrically connected with control circuit 5.

As shown in Fig. 2, the control circuit 5 includes control chip U6 and IC chip U5.

The control chip U6 is 555 timers, and 555 timers are a kind of middle scales that analog- and digital- function is combined Integrated device；The IC chip U5 is used to detect the output level of control chip U6.2 feet and 6 feet of the control chip U6 are equal It is electrically connected with 1 foot of IC chip U5, as the input terminal of signal, the voltage of input is Ui；Control 3 feet and triode of chip U6 The base stage of Q5 is electrically connected, and as the output end of signal, the voltage of output is Uo；It is supply voltage to control 4 feet of chip U6 and 8 feet Input terminal, the voltage of input is Vcc；Control the 1 foot ground connection of chip U6；7 feet for controlling chip U6 are hanging, 5 foot series resistances It is grounded after R60.Level signals of the chip U6 according to input terminal is controlled, 3 feet export pre-designed required level signal, Wherein, the level signal of 3 feet output is divided into high level and low level two states, which is required to rely on output end Signal maintains, memoryless function.Work as Ui<When 1/3Vcc, the threshold voltage of Uo=1, output switching activity are 1/3Vcc；Work as Ui>2/ When 3Vcc, the threshold voltage of Uo=0, output switching activity are 2/3Vc.

2 feet and 3 feet of IC chip U5 are electrically connected with voltage and current sample circuit 3, the input terminal as signal.

When battery is in charged state, the 2 foot level of IC chip U5 are higher than 3 foot level, through amplification inside IC chip U5 Afterwards, 1 foot of IC chip U5 exports low level, and is transmitted to the input letter of 2 feet and 6 feet of control chip U6 as control chip U6 Number, after control chip U6 receives the low level signals of 2 feet and 6 feet, the 3 feet output of control chip U6 is high level, therefore three The base stage of pole pipe Q5 is high level, and the grid of field-effect tube Q6 is moved to low level by triode Q5 conductings after triode Q5 conductings, To make field-effect tube Q6 be connected, power supply is output to D/C voltage output circuit 3 from the source electrode of field-effect tube Q6.

After battery is fully charged, the 2 foot level of IC chip U5 are less than 3 foot level, and 1 foot of IC chip U5 exports high level, And it is transmitted to the input signal of 2 feet and 6 feet of control chip U6 as control chip U6, control chip U6 receives 2 feet and 6 feet High level signal after, the 3 feet output of control chip U6 is low level, therefore the base stage of triode Q5 is low level, triode Q5 ends, and the grid of field-effect tube Q6 is high level after triode Q5 cut-offs, and power supply output has been cut off in field-effect tube Q6 cut-offs, It is disconnected the connection of charger and battery.

False triggering action caused by pulse signal and the interference of other noise signals when in order to avoid power source circuit switch, In circuit be added for delay cutoff protection circuit capacitance C24, the capacitance C24 one end series resistance R51 after respectively with Control the 1 foot electrical connection of 2,6 feet and IC chip U5 of chip U6, the other end ground connection of the capacitance C24.When the 1 of IC chip U5 When foot exports high level, capacitance C24 is started to charge up, and charge constant is 1.1* (R40+R58) * C24, when the electricity of capacitance C24 When amount is charged to the threshold voltage of output switching activity when 2/3Vcc, output loop of cutting off the power, delay time is set as 1 second or so.This A protection circuit not only protects cell voltage to pour in down a chimney charger, and the no-voltage for also achieving battery enters, and then improves entire The reliability of charging system.

Above-described embodiment is the preferable realization method of the utility model, is not the restriction to the utility model, not Under the premise of being detached from the utility model design, any obvious replacement both is within the protection scope of the present invention.

Claims

1. a kind of lithium battery, which is full of, automatically cuts off protection circuit, it is characterised in that：Including secondary commutation filter circuit (1), cut-out Switching circuit (2), D/C voltage output circuit (3), voltage and current sample circuit (4) and control circuit (5), the secondary commutation filter Wave circuit (1), cut-out switch circuit (2), D/C voltage output circuit (3), voltage and current sample circuit (4) and control circuit (5) Sequence is electrically connected, and the control circuit (5) is also electrically connected with cut-out switch circuit (2).

2. lithium battery according to claim 1, which is full of, automatically cuts off protection circuit, it is characterised in that：The control circuit (5) include that control chip U6 and IC chip U5, the control chip U6 and IC chip U5 are electrically connected, the IC chip U5 and voltage Current sampling circuit (4) is electrically connected；

The cut-out switch circuit (2) includes triode Q5 and field-effect tube Q6；

The drain electrode of the field-effect tube Q6 is electrically connected with the output end of secondary commutation filter circuit (1), the D/C voltage output electricity The input terminal on road (3) is electrically connected with the source electrode of field-effect tube Q6, the collector of the grid and triode Q5 of the field-effect tube Q6 Electrical connection, the base stage and emitter of the triode Q5 are electrically connected with control chip U6.

3. lithium battery according to claim 2, which is full of, automatically cuts off protection circuit, it is characterised in that：The control chip U6 Also be electrically connected with for delay cutoff, protect circuit capacitance C24, the capacitance C24 one end series resistance R51 after respectively with Control chip U6 and IC chip U5 electrical connections, the other end ground connection of the capacitance C24.

4. lithium battery according to claim 3, which is full of, automatically cuts off protection circuit, it is characterised in that：The control chip U6 For 555 timers.

5. being full of according to claim 1-4 any one of them lithium batteries and automatically cutting off protection circuit, it is characterised in that：The electricity Current voltage sample circuit (4) is also electrically connected with feedback control circuit (6), the feedback control circuit (6) also with control circuit (5) Electrical connection.